Today I drove the car and it got couple of missing boost under 2nd gear acceleration..Then I got the CEL on for 10 secs and went off.I just back home and used the OBD tool readed the pending code whichs P031A.I can't find any information about this code.Anyone know whats it mean please help..

I will be to the dealer workshop next week to replace my stock clutch whichs nearly dead under the EVT700 kit so I might have to check this out as well.but if anyone know anything please let me know as I am so curious about this...

 

Did you switch to catless exhaust without reflashing the software?

 

Yes going to send back for a reflash soon.
After some research I think I got a bit idea why my car running slower and slower and now even missing boost..Nothing to do with the cat-less
I been running 108 leaded racing fuel mix with 50% 93 unleaded for couple of weeks.Might be my spark plugs got damage by leaded fuel so the car ran bad.Will replace them tomorrow first and see whats going on.

 

btw I think P031A is a cylender miss-fire code.

 

Your problem is most likely caused by 108 leaded fuel. My guess is your plugs are toast.